function collect_same_elements(collection_a, collection_b) {
  var arr=[];
  // let s1=collection_a.map(function(x){
  //           return Number(x);
  // });
  // let s2=collection_b.map(function(x){
  //   return Number(x);
  // });
 for(var ai=0;ai<collection_a.length;ai++){
   for(var bi=0;bi<collection_b.length;bi++){
     if(collection_a[ai]==collection_b[bi]){
       arr.push(collection_a[ai]);
     }
   }
 }
 console.log(arr);
  return arr;//在这里写入代码
}

module.exports = collect_same_elements;
